State Sen. Heather Steans, D-Chicago, was up for reelection last year, so she entered the March primary, got the Democratic nomination for her district, raised roughly $94,300 over several months and won unopposed in the general election.

This month, she and her colleagues were sworn in as the 102nd General Assembly convened. But a few days later, saying it was time for “fresh eyes and fresh energy,” she announced her resignation, effective Jan. 31.

Steans cited family responsibilities, including the needs of her mother, who has Alzheimer’s disease. We were unable to reach her for a more detailed explanation. But really, if you don’t want the job, don’t run.

She leaves office with a campaign account — donations from citizens, businesses, political committees and unions who supported her continued role in the Senate — carrying at least $325,000 that she can spend on other political activities. Illinois election law is pretty loose on the rules.

And political insiders, not voters, will now choose her replacement to finish her two-year term.

Steans’ departure may sound like an oddly abrupt decision for someone not being forced out by scandal. But it’s commonplace in Illinois. Incumbent politicians often enter reelection races only to drop out after winning the primary or resign after taking office. The day before Steans announced her resignation, Sen. Andy Manar, D-Bunker Hill, left to take a job with Gov. J.B. Pritzker. Back in 2008, as it happens, Steans arrived in the Senate after being appointed, not elected.

We don’t begrudge anyone who suddenly faces unforeseen obligations or gets new opportunities that are too good to pass up. But when elected legislators bail out, voters are deprived of the person they chose to represent them — and deprived of a role in the replacement.

Instead of holding new elections to fill legislative vacancies, as 25 states do, Illinois assigns the task to local party committees. The departing lawmaker often gets a say in who it will be. State Rep. Kelly Cassidy, who reportedly plans to seek the appointment, will have 22% of the weighted vote in the choice of Steans’ successor through her role as a party leader in the 49th Ward. So Cassidy can put herself at the front of the line. Chicago Ald. Harry Osterman, 48th, will hold a 27% share of the weighted vote on Steans’ replacement.

This is not healthy for democracy. It encourages cynicism among voters — rightfully so — that is already in high supply. It feeds distrust in government that carries serious consequences of frustration, numbness and disengagement.

Steans is an accomplished lawmaker who has won our endorsement multiple times. When she announced her resignation, Senate President Dan Harmon, praised her as “a forceful advocate for progress and problem solving, who fearlessly tackled many of the biggest issues in our society and was always looking for her next challenge.”

We regret her departure partly because it deprives Springfield of her expertise. But we especially regret that Steans has disappointed voters who assumed she was prepared to do the job for the next two years. Had she decided not to run for reelection, there might have been a wide-open contest for the seat. As it is, voters won’t get to weigh in until 2022, when her successor will have all the advantages of incumbency.

In November, voters decided they wanted Steans to continue representing them in Springfield. Too bad what the voters want doesn’t matter.